• 대한핵의학회지
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• 제17권2호
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• pp.41-47
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• 1983

To evaluate the significance of assay of serum thyroglobulin(Tg) in monitoring the course of the thyroid cancer or its response to treatment, serum thyroglobulin levels were measured in 41 patients with thyroid cancer who visited Seoul National University Hospital from August, 1981 to August, 1982. The results were as follows: 1) Serum Tg levels $1\sim3$ months after thyroidectomy was $31{\pm}23$ ng/ml$(mean{\pm}S.D.)$ in 14 patients without metastasis, $66{\pm}41$ ng/ml in 21 patients with regional metastasis and $176{\pm}59$ ng/ml in 6 patients with distant metastasis and there were significant differences among three groups(p<0.01). 2) Serum Tg levels in 13 patients with metastasis before and after $^{131}I$ treatment were $134{\pm}62ng/ml$ and $67{\pm}52ng/ml$ respectively. 3) In the follow-up measurement of serum Tg levels every 3 months for about 1 year, almost all serum Tg levels were below 60 ng/ml in 12 patients without distant metastasis and serum Tg levels were elevated above 60 ng/ml in 5 of 6 patients with distant metastasis. 4) In 6 patients with distant metastasis, serum Tg levels were elevated in 5 patients and $^{131}I$ whole body scan showed definite metastatic evidence in 3 patients and suspicious evidence in 1 patient. From above results, we concluded that serum Tg level is very useful as an indicator of recurrence or metastasis in patients with thyroid cancer after operation.

• Journal of Computing Science and Engineering
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• 제6권1호
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• pp.1-11
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• 2012

Computed tomography (CT) images are widely used for the analysis of the temporal evaluation or monitoring of the progression of a disease. The follow-up examinations of CT scan images of the same patient require a 3D registration technique. In this paper, an automatic and robust registration is proposed for the rigid registration of 3D CT images. The proposed method involves two steps. Firstly, the two CT volumes are aligned based on their principal axes, and then, the alignment from the previous step is refined by the optimization of the similarity score of the image's voxel. Normalized cross correlation (NCC) is used as a similarity metric and a downhill simplex method is employed to find out the optimal score. The performance of the algorithm is evaluated on phantom images and knee synthetic CT images. By the extraction of the initial transformation parameters with principal axis of the binary volumes, the searching space to find out the parameters is reduced in the optimization step. Thus, the overall registration time is algorithmically decreased without the deterioration of the accuracy. The preliminary experimental results of the study demonstrate that the proposed method can be applied to rigid registration problems of real patient images.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 1998년도 Proceedings of International Symposium on Remote Sensing
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• pp.301-306
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• 1998

Korea Aerospace Research Institute (KARI) is developing a Korea Multi-Purpose Satellite I (KOMPSAT-I) which accommodates Electro-Optical Camera (EOC), Ocean Scanning Multi-spectral Imager (OSMI), and Space Physics Sensor (SPS). The satellite has the weight of about 500kg and will be operated on the 10:50 AM sun-synchronized orbit with the altitude of 685 km. The satellite will be launched in 1999 and its lifetime is expected to be over 3 years. The main mission of EOC is the cartography to provide the images from a remote earth view for the production of 1/25000-scale maps of KOREA. EOC collects 510 ~ 730 nm panchromatic imagery with the ground sample distance(GSD) of 6.6 m and the swath width of 17 km by push broom scanning. EOC also can scan $\pm$45 degree across the ground track using body pointing method. The primary mission of OSMI is worldwide ocean color monitoring for the study of biological oceanography. It will generate 6 band ocean color images with 800 km swath width and 1km GSD by whiskbroom scanning. OSMI is designed to provide on-orbit spectral band selectability in the spectral range from 400 nm to 900 nm through ground command. This flexibility in band selection can be used for various applications and will provide research opportunities to support the next generation sensor design. SPS consists of High Energy Particle Detector (HEPD) and ionosphere Measurement Sensor (IMS). HEPD has missions to characterize the low altitude high-energy Particle environment and to study the effects of radiation environment on microelectronics. IMS measures densities and temperature of electrons in the ionosphere and monitors the ionospheric irregularities at the KOMPSAT orbit.

• Composites Research
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• 제16권1호
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• pp.26-33
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• 2003

열-음향방출(thermo-acoustic emission)기법을 이용함으로써, 직교형 복합재료적층판의 저온냉각 시에 형성되는 미세손상을 검출하고 평가하여 그 유효성을 검토하였다. 액체질소에 의한 저온냉각($-191^{\circ}C$)으로 생성된 미세손상은 가열-냉각 열부하사이클 시에 발생하는 음향방출(AE)거동의 해석을 통해 평가되었다. 저온냉각에 따른 섬유파단과 모재파손은 초음파 C스캔, 광학현미경, 주사형 전자현미경을 통해 관찰되었으며, 이들 미세파손 모드는 AE신호의 퓨리에 변환(FFT)처리해석, 단시간 퓨리에 변환(STFT)처리해석으로 분류되는 3종류의 서로 다른 특징을 갖는 AE신호로 검출될 수 있었다. 이들 AE신호특성을 시간 단계별로 검출하여 저온냉각시에 형성되는 복합재료 미세파괴의 과정을 실시간으로 평가할 수 있었으며, 또한 열부하 사이클시의 AE신호해석을 통해서 저온 냉각으로 생성된 미세파손의 정도를 추정할 수 있었다.

• 한국정보전자통신기술학회논문지
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• 제5권3호
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• pp.138-143
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• 2012

본 연구에서는 기존의 사용되고 있던 혈당 측정에 대한 번거로움을 줄이기 위해 단일화 스트립지 교환기 개발에 대한 연구를 진행하였다. 스트립지 케이스는 탄창식으로 제작하여 기존 제품 사용시 발생했던 손 오염이나 분실률을 최소화하였으며, 또한 스트립지의 정량을 실시간으로 확인 가능하게 하여 환자의 편리성을 추구하였다. 연구에선 특정 제품의 스트립지를 사용하였으나 이는 단순 연구에 대한 예시로 타 스트립지마다 제작이 가능하다. 제안한 단일화 스트립지 교환기는 설문지를 작성을 통해 평가 및 만족도를 조사하여 데이터를 구축하였고, 구매의사에 대한 문항에 67%로 좋은 평가를 받았다. 연구는 흔히 발병하는 당뇨병 환자의 자가 검사 시 겪는 불편함을 최소화하려하였으며, 나아가 실용성을 추구한 디자인을 통해 기능성과 실용성을 개선하여 다양한 질병의 스트립지에 대한 응용 가능성을 제시하였다.

• Journal of Oral Medicine and Pain
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• 제44권2호
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• pp.45-53
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• 2019

Purpose: To determine whether crepitus may be a clinical indication for early temporomandibular joint (TMJ) osteoarthritis (OA) and to investigate the correlation between crepitus and the occurrence of TMJ OA with respect to factors, such as patient sex, age, chewing habits, and diagnosis. Methods: This is retrospective analysis of clinical data for 162 TMJs. The criteria for a joint to be included in this study was a minimum of two cone-beam computed tomography (CBCT) scans performed with no OA observed during the initial scan. The Diagnostic Criteria for Temporomandibular Disorders was used for OA diagnosis. Crepitus was recorded when it was objectively palpated during the follow-up period. Correlations between various patient factors and progression to TMJ OA were calculated using the Pearson's chi-square test. A linear-by-linear association was used to analyze trends of OA progression with increasing age. Results: Among the 162 joints, 101 progressed to OA and 61 did not. In the joints where crepitus had been present before OA was confirmed at next or last CBCT, OA progressed at a high rate, and especially higher in female and older patients (p<0.01). Patients in the pain-related disorder group with crepitus were observed to have higher rates of OA progression compared to patients in the intra-articular disorder group (p<0.01). Conclusions: If a patient experiences pain in the TMJs and crepitus, close monitoring through regular CBCT scans is necessary even if there is no evidence of radiologically confirmed OA after the first CBCT.

• Journal of Radiation Protection and Research
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• 제46권4호
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• pp.194-203
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• 2021

Background: Surface soil radiation monitoring around nuclear facilities is important to classify and characterize the contaminated areas. A scanning and direct measurement technique can survey the sites rapidly before starting sampling analysis. Materials and Methods: Regarding this, we test and suggest a measurement technique for gross alpha/beta and ⁹⁰Sr activities in surface soil based on a mobile ZnS(Ag)/PVT (polyvinyltoluene) array and a handheld PVT rod, respectively. To detect ⁹⁰Sr selectively in soil mixed with naturally occurring radioactive materials, chosen energy channel counts from the multichannel analyzers were used instead of whole channel counts. Soil samples contaminated with exempt liquid ⁹⁰Sr with 1 Bq·g^-1, 3 Bq·g^-1, and 10 Bq·g^-1 were prepared and hardened by flocculation. Results and Discussion: The mobile ZnS(Ag)/PVT array could discriminate gross alpha, gross beta, and gamma radiation by the different pulse-shaped signal features of each sensor material. If the array is deployed on a vehicle, the scan minimum detectable concentration (MDC) range will be about 0.11-0.17 Bq·g^-1 at 18 km·h^-1 speed, highly sensitive to actual sites. The handheld PVT rod with 12 mm (Φ) × 20 mm (H) size can directly measure ⁹⁰Sr selectively if channels on which energies are from 1,470 and 2,279 keV are gated, minimizing crossdetection of other radionuclides. These methods were verified by measuring soil samples fabricated with homogeneous ⁹⁰Sr concentrations, showing static MDC of 2.16 Bq·g^-1 at a measurement time of 300 seconds. Conclusion: Based on the results, comprehensive procedures using these detectors are suggested to optimize soil sites survey.

• 전기화학회지
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• 제27권1호
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• pp.15-31
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• 2024

The antimalarial drug hydroxychloroquine sulphate (HCQ) has taken much attention during the first COVID-19 pandemic phase for the treatment of severe acute respiratory infection (SARI) patients. Hence it is interest to study the electrochemical properties and photocatalytic degradation of the HCQ drug. Copper oxide (CuO) nanoparticles, graphene oxide (GO) and CuO/GO NC (nanocomposite) modified carbon paste electrodes (MCPE) are used for the detection of HCQ in an aqueous medium. Electrochemical behaviour of HCQ (20 μM) was observed using CuO/MCPE, GO/MCPE and CuO/GO NC/MCPE in 0.1 M phosphate buffer at pH 7 with a scan rate of 20 to 120 mV s^-1 by cyclic voltammetry (CV). Differential pulse voltammetry (DPV) of HCQ was performed for 0.6 to 16 μM HCQ. The CuO/GO NC/MCPE showed a reasonably good sensitivity of 0.33 to 0.44 μA μM cm^-2 with LOD of 69 to 92 nM for HCQ. Furthermore, the CuO/GO NC was used as a catalyst for the photodegradation of HCQ by monitoring its UV-Vis absorption spectra. About 98% was degraded in about 34 min under visible light and after 4 cycles it was 87%. The improved photocatalytic activity may be attributed to decrease in bandgap energy and enhanced ability for the electrons to migrate. Thus, CuO/GO NC showed good results for both sensing and degradation applications as well as reproducibility.

• 대한원격탐사학회지
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• 제22권2호
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• pp.141-151
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• 2006

태양광을 광원으로 하고 천정방향을 포함한 다양한 고도각을 이용하는 자외선/가시광선영역에서의 흡수분광학이 최근에 지상용 대기원격 측정에 개발되어오고 있다. 이를 이용하여 지표부근에 존재하는 대기 미량 물질의 공간적 분포가 유추될 수 있다. 대기질 측정기술 중 하나인 MAX-DOAS (Multi-axis Differential Optical Absorption Spectroscopy) 기술은 광원으로서 태양산란광을 이용하고, 다양한 고도각에서 태양산란광을 기록하고 분석을 통하여 대기 중 미량 물질을 측정한다. 광주과학기술원 환경모니터링 신기술 연구센터에서 개발된 MAX-DOAS 시스템은 9004년 1월, 5월, 10월에 각각 도시대기, 화산플룸, 화력발전소 플룸의 측정에 적용되었다. 각각의 경우에 $SO_2,\;NO_2,\;BrO,\;O_4$를 정량분석하기 위하여 기록된 MAX-DOAS 스펙트럼은 자외선/가시광선 영역에서의 고유 흡수스펙트럼을 이용한 DOAS 기술을 이용하여 분석 되었다. 그 결과는 Slant Column Density (SCD)로 표현되었다. 플룸 측정의 경우에서는 플룸 속에 포함된 $NO_2,\;SO_2$의 공간적 분포를 파악하기 위하여 플룸의 진행방향과 수직적인 방향에서 MAX-DOAS 스캔이 이루어졌다. 이를 통하여 얻은 단면적을 토대로 $SO_2,\;NO_2$ 농도가 계산되었다. 화산플룸에서 $SO_2$는 580ppbv, 화력발전소 플룸에서 $NO_2$는 337ppbv, $SO_2$는 227ppbv 로 계산되었다.

• 자원환경지질
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• 제55권5호
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• pp.497-510
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• 2022

포항 달전리 주상절리(천연기념물 제415호)에서 발생하고 있는 낙석의 원인을 파악하기 위해 2018년 1월부터 2022년 8월까지 월별 모니터링과 3차원 스캔 측량, 전기 비저항탐사를 실시하였다. 약 5년간 주상절리대에서 떨어져 나온 낙석은 총 3,231개이며, 낙석의 크기(길이)는 20cm 이하가 1,521개(47%)로 가장 많고, 20~30cm는 978(30.3%), 30cm 이상은 732개(22.7%)가 발생하였다. 2018년부터 연도별 낙석 발생 개수는 감소하는 반면, 30cm 이상의 낙석 발생 빈도는 증가하는 경향을 보인다. 대규모의 낙석은 해빙기(3월~4월)와 장마기(6월~7월)에 주로 발생하였으며, 누적강우량과 낙석 발생 관계 분석에서 3~4일 간의 누적강우량도 낙석 발생에 밀접한 관계가 있는 것으로 나타났다. 주상절리 내의 사면물질(충진물)을 대상으로 한 XRD 분석에서 팽창성 점토광물인 스멕타이트와 일라이트가 관찰되었으며 전기비저항탐사에서 단층파쇄대가 존재하는 것이 확인되었다. 또한, 확인된 단층파쇄대와 3D 정밀측정을 통해 분석된 최대 침식지점이 무인카메라에서 관찰된 주 낙석 발생 지점과 일치하였다. 따라서 포항 달전리 주상절리의 낙석 발생 주요 원인은 내부요인(단층파쇄대와 절리의 발달, 암석의 풍화, 팽창성 점토광물의 존재)과 외부요인(강우량, 해빙기 급속한 융해현상)이 복합적으로 작용하여 대규모 낙석을 발생하는 것으로 판단된다. 반면, 일부에서 지속적으로 제기 되었던 포항-경주 지진은 주요 원인이 아님이 확인되었다.